1Heat gas or charcoal grill. In large bowl, mix beef, beans, cracker crumbs, 2 tablespoons barbecue sauce, the pepper and egg. Shape into 5 patties, about 1/2 inch thick.
2Brush grill rack with vegetable oil. Place patties on grill. Cover grill; cook over medium heat 5 minutes. Turn; cook covered 5 to 6 minutes longer or until meat thermometer inserted in center of patties reads 160ºF.
3Place lettuce and patties on bottom halves of buns. Spread each patty with 1 teaspoon barbecue sauce. Top with tomato and onion. Cover with bun tops.